66121387200 has 504 divisors, whose sum is σ = 258976678896. Its totient is φ = 15866880000.

The previous prime is 66121387193. The next prime is 66121387217. The reversal of 66121387200 is 278312166.

66121387200 is a `hidden beast` number, since 6 + 612 + 1 + 38 + 7 + 2 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 15996334 + ... + 16000466.

Almost surely, 2^66121387200 is an apocalyptic number.

66121387200 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66121387200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (129488339448).

66121387200 is an abundant number, since it is smaller than the sum of its proper divisors (192855291696).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66121387200 is a wasteful number, since it uses less digits than its factorization.

66121387200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4273 (or 4255 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

Adding to 66121387200 its reverse (278312166), we get a palindrome (66399699366).

The spelling of 66121387200 in words is "sixty-six billion, one hundred twenty-one million, three hundred eighty-seven thousand, two hundred".